The Experts below are selected from a list of 258 Experts worldwide ranked by ideXlab platform
Witold M. Paczkowski - One of the best experts on this subject based on the ideXlab platform.
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Discrete Multicriterion Optimization of a Space Truss
International Journal of Space Structures, 1994Co-Authors: Jan A. Karczewski, Witold M. PaczkowskiAbstract:Final forming of a space truss used as roof in a sports or market hall is a result of searching for a solution which is the best one according to various criteria such as safety, reliability, economy, functionality and so forth. An illustration of this problem a numerical example of various Optimizations of an orthogonal, double layer space truss of dimensions 24 × 24 m made of steel is shown in the paper. First, eight single-criterion objective functions such as: weight of members, weight of nodes, weight of columns, weight of whole truss, weight of walls and roofing elements made of steel, vertical displacements of a node in the middle of the truss, energy of deformation and a certain function of geometry of the truss were investigated assuming the number of divisions and the depth of the truss as decisive variables. The problems were formulated as discrete ones since the element cross-sections were selected from a finite catalogue. The All Variants Inspections Method was employed. For three among the aforementioned objective functions, describing weight of structure, displacement of the central node and the geometry of the truss, a discrete Multicriterion Optimization problem was formulated and solved. From the set of compromises a preferred sollution has been chosen by using the discrete functions and, the global criterion method.
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Multicriterion Optimization of Large Scale Mechanical Systems
Concurrent Engineering: Tools and Technologies for Mechanical System Design, 1993Co-Authors: Stefan Jendo, Witold M. PaczkowskiAbstract:The paper deals with discussion of Optimization problems in engineering structural design. The following questions are discussed: continuous or discrete Optimization, single-or multicriteria Optimization, one-or multilevel Optimization. The paper is illustrated with example of Multicriterion discrete Optimization of large scale truss systems.
Zb. Pater - One of the best experts on this subject based on the ideXlab platform.
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Selection of geometric parameters of transverse wedge rolling tools
Journal of Materials Processing Technology, 1992Co-Authors: W. Weroński, Zb. PaterAbstract:Abstract The developed subject covers problems of modernization of the rolling technology for drawn forgings. A transverse wedge rolling process was employed for forming the blanks. A method of selection of geometric parameters of wedge-shaped dies has been presented, based upon Multicriterion Optimization.
Olivier Pironneau - One of the best experts on this subject based on the ideXlab platform.
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SHAPE Optimization IN FLUID MECHANICS
Annual Review of Fluid Mechanics, 2004Co-Authors: Bijan Mohammadi, Olivier PironneauAbstract:▪ AbstractThis paper is a short and nonexhaustive survey of some recent developments in optimal shape design (OSD) for fluids. OSD is an interesting field both mathematically and for industrial applications. Existence, sensitivity, and compatibility of discretizations are important theoretical issues. Efficient algorithmic implementations with low complexity are also critical. In this paper we discuss topological Optimization, algorithmic differentiation, gradient smoothers, Computer Aided Design (CAD)-free platforms and shock differentiation; all these are applied to a Multicriterion Optimization for a supersonic business jet.
W. Weroński - One of the best experts on this subject based on the ideXlab platform.
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Selection of geometric parameters of transverse wedge rolling tools
Journal of Materials Processing Technology, 1992Co-Authors: W. Weroński, Zb. PaterAbstract:Abstract The developed subject covers problems of modernization of the rolling technology for drawn forgings. A transverse wedge rolling process was employed for forming the blanks. A method of selection of geometric parameters of wedge-shaped dies has been presented, based upon Multicriterion Optimization.
Marvin D. Troutt - One of the best experts on this subject based on the ideXlab platform.
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Solving electronic spreadsheet models by interactive Multicriterion Optimization: a budgeting illustration
Journal of the Operational Research Society, 2001Co-Authors: Marvin D. Troutt, Bee K. Yew, Aimao ZhangAbstract:In previous papers a connection between general spreadsheet models and interactive Multicriterion Optimization has been discussed. The purpose of the present paper is to provide proof of the concept with a detailed example. The main idea is that interactive Multicriterion Optimization can be viewed as a new way of interacting with spreadsheet models. It offers advantages over the two prevailing ones, namely what-if and goal-seeking. A simplified budgeting example is given to clarify this connection. Directions of improvement are assumed to be provided by the decision maker using one of the several existing methods. One improvement iteration is illustrated and analyzed following the method of Loganathan and Sherali.
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Pairwise agreement of gradient directions in interactive Multicriterion Optimization
Journal of Multi-Criteria Decision Analysis, 1994Co-Authors: Marvin D. TrouttAbstract:Statistical tests involving mean directions have in the past been limited to two- and three-dimensional settings, perhaps owing to their primary applications to such fields as geology, meteorology and related earth sciences. In the study of interactive Multicriterion Optimization it becomes necessary to compare gradient directions obtained from decision makers by two or more methods. Typically these direction vectors are in a higher-dimensional space. This paper provides a general procedure based on Householder transformations which is potentially suitable for any finite dimension. An illustration and comparison of the method are provided.
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Direction-specific gradient scaling for interactive Multicriterion Optimization using an abstract mass concept
Operations Research, 1994Co-Authors: Marvin D. TrouttAbstract:In the Method of Abstract Forces for the direction finding (or tradeoff cut) subproblems of interactive Multicriterion Optimization, it is necessary to scale criterion gradients. Previously, an ad hoc, analyst assisted, but nevertheless effective scaling method was used. This paper introduces a concept of abstract mass. It is shown that the previous ad hoc scaling method may be considered an approximation to the present direction-specific approach. Also, the abstract mass approach provides a strengthening of the original Newton's Second Law of Motion analogy motivation for the Method of Abstract Forces. A method for automatic and direction-specific scaling is proposed which depends on the solution of a continuous piecewise polynomial system of equations. The method is illustrated on an example with three criterion functions. In this example, Newton's method for solving simultaneous nonlinear systems converges to a solution. More generally, restart homotopy methods may be required.
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Method of forces for direction finding in interactive Multicriterion Optimization applications
Journal of Optimization Theory and Applications, 1991Co-Authors: Marvin D. Troutt, Roy J. Clinton, Tom HemmingAbstract:The main purpose of this paper is to derive, illustrate, and validate a method of direction finding for use in Multicriterion interactive Optimization applications. A secondary purpose is to consider electronic spreadsheet operation as an instance of interactive Multicriterion Optimization and to test the new method in a spreadsheet model for aggregate production planning. The method derived here amounts to virtual direct specification of the gradient direction, but does so by an appeal to the simple physical notion of forces applied to the criteria. It is demonstrated that the idea is easily grasped and also gives effective performance in the application tested.
